Chempro

EFFECT OF VARIATION OF BACTERI STARTER CONCENTRATION AND LENGTH OF FERMENTATION ON UHT MILK YOGURT

Imas Masruroh Masruroh — 2024-12-20

Yogurt is a fermented beverage formed due to bacteria that break down the sugar in milk, lactose, into lactic acid. Low pH can inhibit pathogenic microorganisms, spoilers, and toxin-producing microorganisms will die. The function of probiotic bacteria contained in yogurt is its ability to kill bad bacteria found in the digestive tract. In this test, the bacterial starter used was plain and yakult yogurt containing Streptococcus thermophilus and Lactobacillus bulgaricus with a concentration of 2% and 5% of the volume of milk used with a fermentation/incubation time of 12 hours and 24 hours. Based on sample tests with variations in bacterial starter concentrations and different fermentation periods, it was found that yogurt with a bacterial starter with a concentration of 2% had a lower level of acidity, a slightly sour aroma, and a thinner viscosity texture than yogurt using a bacterial starter with a concentration of 5%, a distinctive aroma of yogurt that was more sour and a plain taste typical of yogurt and more sour than the 2% concentration. The aroma of yogurt is caused by the amount of lactic acid bacteria that are fermented in it. Likewise, the texture of yogurt is influenced by the use of ingredients and fermentation time. The
longer the fermentation time, the thicker the texture. Based on the test results of 12 hours and 24 hours fermentation time, the level of viscosity, aroma, and taste at 24 hours fermentation time is higher than 12 hours fermentation time.

The Effect of Pressure Application on Reverse Osmosis Membrane Performance in The Brackish Water Treatment Process

Claudia Shinta Octa Wibowo — 2024-12-20

One of the clean water treatment technologies uses reverse osmosis membranes. Reverse osmosis is a water purification process that, in principle, uses the help of hydrostatic pressure so that the solvent can move from a high-concentration solution to a low-concentration solution. This experiment was conducted using 9% brackish water and applying pressure to the membrane of 50, 54, and 58 psi. Observations were made on pre-treatment, permeate, and retentate flow samples. The results of the observations showed that increasing pressure would affect the performance of the RO process. This is indicated by the highest rejection and flux values obtained at a variation of 58 psi, which were 0.9989 - 0.9992 and 335.09 L/m²/hour. The application of pressure to the RO process will affect the total dissolved solids produced.

Short Review of Characterization, Treatment, and Application of Malang Zeolite

Devi Lestariningsih — 2024-12-20

Malang natural zeolite is an abundant mineral resource in Indonesia, characterized by its unique microporous structure, making it highly potential for various applications, including wastewater treatment, toxic gas adsorption, and as a catalyst in chemical reactions. This article provides a brief review of the characterization, treatment, and applications of Malang natural zeolite, based on various analytical techniques such as XRD, SEM-EDX, and BET. Additionally, chemical and thermal treatments used to enhance the performance of zeolite in specific applications are also discussed. The research results indicate that Malang natural zeolite holds significant potential in various fields, although further research is needed to evaluate its applications on a larger scale and develop more environmentally friendly treatment methods.

Analysis Boilling Point/End Point Testing Of Gasoline Products Using HAD-620 Atmospheric Destillation

Farlina Hapsari — 2024-12-20

PT Pertamina (Persero) Fuel Terminal Gorontalo contains Avtur, Pertamax, Pertalite, Premium, Solar and Dexlite products. In testing gasoline using Atmospheric Distillation HDA-620. The purpose of this final project is to know the Endpoint testing procedure on gasoline products using HDA-620 Atmospheric Distillation, to know the specifications of the HDA-620 Atmospheric Distillation
equipment based on the oil and gas director and to analyze the contamination of gasoline products. The implementation of the Final Project is carried out by conducting tests at the PT. Pertamina Persero Fuel Terminal Gorontalo laboratory. The results of the gasoline testing process using Atmospheric Distillation HDA-620 are taking samples from the storage tank, testing in the laboratory, the endpoint results are between 144-155oC. The specifications for the HDA-620 atmospheric distillation apparatus
are based on the Director General of Oil and Gas, namely the ISO method which is technically equivalent, which for the IP/ASTM D445 test method uses the ISO 3104 method and the IP123 test method uses the ISO 3405 method. Based on the results of the contamination test by mixing the test samples between premium 600 ml biodiesel 400 ml then tested using HAD-620 Atmospheric
Distilation, the result obtained from contamination from gasoline products has a high density fraction because it has passed specifications and occurs slowly in the evaporation process. The gasoline tasted by researchers was of good quality because it complied with the specifications at the Gorontalo Fuel Terminal

ANALISIS EFEKTIVITAS DSSC (DYE-SENSITIZED SOLAR CELLS) MENGGUNAKAN PEWARNA ALAMI BUAH NAGA DAN BUNGA BUGENVIL SEBAGAI SENSITISATOR

Daniel Agustin — 2024-12-20

Dye-Sensitized Solar Cells (DSSC) is a third generation solar cell technology that utilizes natural dyes as sensitizers to capture sunlight. This research aims to analyze the effectiveness of natural dyes from red dragon fruit (Hylocereus polyrhizus) and bougainvillea flowers (Bougainvillea spectabilis) as sensitizers in making DSSC. The dye was extracted using the maceration method for 24, 36, 48, 56, and 72 hours to study the effect of duration on anthocyanin concentration. The research process involves making TiO2 paste, buffer solution, electrolyte solution, as well as working electrodes and counter electrodes. Dye characterization was carried out using a UV-Vis spectrophotometer to determine the light absorption capability, while DSSC performance was tested using a digital multimeter to evaluate voltage, current and energy conversion efficiency. The results showed that dragon fruit produced higher anthocyanin concentrations and efficiency than bougainvillea flowers at the same maceration duration. DSSC efficiency with dragon fruit reached 0.01305%, while bougainvillea flower reached 0.00637% at a maceration duration of 72 hours.